Patents by Inventor Charles F. Renn

Charles F. Renn has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Arc detector for electric rod furnace
    Patent number: 4376243
    Abstract: A current shunt in the power supply to an electric furnace generates a signal voltage proportional to furnace current. A voltage rate comparator senses a high change rate of signal level corresponding to arcs occurring in the furnace and the comparator output pulse is fed to a preset counter. The counter is reset periodically. If a predetermined number of pulses are registered by the counter within a preset time interval, the counter output will de-energize an output relay which turns the power supply off and energizes a warning signal.
    Type: Grant
    Filed: January 26, 1981
    Date of Patent: March 8, 1983
    Assignee: General Motors Corporation
    Inventors: Charles F. Renn, William J. Koeller